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Playing with js_of_ocaml

A few years ago, while picking up basic OCaml, I found this site by Andrew Ray: https://andrewray.github.io/iocamljs/full402.html . This page has in-browser OCaml notebook. I was trying to modernise it and compile with OCaml 4.06.1. The vital part of the page is an ability to evaluate OCaml at run time in Javascript inside your browser. This is done by Js_of_ocaml. Learn basics of Js_of_ocaml in this post.

Hello World

Let’s do tradition “hello world” exercise, create a new file hello.ml:

let () =  

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type void

(* Core pipe type *)

type ('a, 'b, 'r) pipe =
  | Yield of ('b  * (unit -> ('a, 'b, 'r) pipe))
  | Await of ('a -> ('a, 'b, 'r) pipe)
  | Ready of 'r

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Multisignature

This sentence is a procedure for n-of-n Multisignatures to the following URL.

The symbols and functions used are defined in the following URL.

https://github.com/sipa/bips/blob/bip-schnorr/bip-schnorr.mediawiki

Introduction

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Threshold Signatures

This text is a procedure for t-of-k threshold signatures.

The symbols and functions used are defined in the following URL.

https://github.com/sipa/bips/blob/bip-schnorr/bip-schnorr.mediawiki

Introduction

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Free eye check for my fellow C++03 devs, what's wrong with this:

for (size_t idx = myVector.size() - 1; idx >= 0; ++idx)
{
    doSomething(myVector[idx]);     
}

for (size_t idx = myVector.size() - 1; idx >= 0; --idx)
{

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module Peano = struct
  type z = Zero
  type 'a s = Succ

  type 'a t =
    | Z : z t
    | S : 'a t -> 'a s t
  and zero = z t

  let zero : z t = Z

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Git Cheatsheet

See Remote Branch Being Tracked

https://stackoverflow.com/questions/171550/find-out-which-remote-branch-a-local-branch-is-tracking

$ git branch -vv

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# Raw transaction API example work-through
# Send coins to a 2-of-3 multisig, then spend them.
#
# For this example, I'm using these three keypairs (public/private)
# 0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86 / 5JaTXbAUmfPYZFRwrYaALK48fN6sFJp4rHqq2QSXs8ucfpE4yQU
# 04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec6874 / 5Jb7fCeh1Wtm4yBBg3q3XbT6B525i17kVhy3vMC9AqfR6FH2qGk
# 048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d46213 / 5JFjmGo5Fww9p8gvx48qBYDJNAzR9pmH5S389axMtDyPT8ddqmw

# First: combine the three keys into a multisig address:
./bitcoind createmultisig 2 '["0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86","04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a9

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Using Git

Global Settings

• Related Setup: https://gist.github.com/hofmannsven/6814278
• Related Pro Tips: https://ochronus.com/git-tips-from-the-trenches/
• Interactive Beginners Tutorial: http://try.github.io/
• Git Cheatsheet by GitHub: https://services.github.com/on-demand/downloads/github-git-cheat-sheet/

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Monadic operations in C++

This began as a further attempt to implement the Maybe monad in C++, but quickly spiralled out of control and now includes an implementation of the List monad as well (using std::list!). This is really for my own amusement rather than to try and do anything useful with them. It also gave me an excuse to try out C++ 11 lambda functions for the first time.

My original implementation defined a macro called MBind which caused a number of problems -- thankfully [PJayB][pjayb] managed to find a way around that so